The white suspect in the massacre at a historic black church in South Carolina is scheduled to make a court appearance Friday for a bail hearing, as federal authorities continue to investigate the killings as a possible hate crime.

Dylann Roof, 21, was flown back to South Carolina Thursday in the custody of the FBI.

He had driven to neighboring North Carolina after allegedly murdering nine worshippers, including an 87-year-old woman, and wounding three more inside the Emanuel African Methodist Episcopal Church in Charleston Wednesday night.

Police said Roof walked into the church and sat quietly for an hour during a Bible study before standing up and saying he had to kill black people.

'Do what I have to do'

A relative of one of the victims told CNN that a survivor told her Roof told the study group, who were all black, that "you've raped our women and you're taking over the country. I have to do what I have to do."

Two Charleston police officers stand in front of the Emanuel AME Church following a shooting Wednesday night in Charleston, S.C., June 18, 2015.

The Associated Press quoted a friend of Roof, who recently reconnected with him, as saying the suspect had complained that "blacks were taking over the world'' and that "someone needed to do something about it for the white race.''

South Carolina Gov. Nikki Haley said Friday the suspect in the deadly church shooting should face the death penalty if convicted.

Who is Roof?

Little is known about Roof. Court documents show he was arrested on two separate occasions at a shopping mall this year for a drug offense and trespassing. And two school districts where he attended high school have no records of him ever graduating.

An uncle, Carson Cowles, told Reuters that Roof's father had recently given him a .45-caliber handgun as a birthday present and that Roof had seemed adrift.

Meanwhile, Charleston announced a prayer vigil for the victims will be held Friday night.

Charleston Mayor Joseph Riley said the shootings were an act of "pure, pure concentrated evil."

Cornell Williams Brooks, the president of the National Association for the Advancement of Colored People, said, "There is no greater coward than a criminal who enters a house of God and slaughters innocent people."

Charleston is known locally as "The Holy City," due to its large number of churches, many of them community anchors for a diverse range of ethnic groups.

A spontaneous memorial for the victims is growing outside Mother Emanuel, as the church is affectionately known, as people bring flowers, balloons and placards in remembrance of the victims.

The shooting marks one of the most notorious attacks on a black church in the South since the 1963 bombing of the 16th Street Baptist Church in Birmingham, Alabama, which killed four girls and helped galvanize the U.S. civil rights movement. The bombing was tied to the Ku Klux Klan.

Prayer vigils in support of the victims were held in churches across the U.S. Thursday.

The Reverend Sidney Davis leads a group in prayer during a community prayer service at the Second Presbyterian Church near the Emanuel AME Church in Charleston, S.C., June 18, 2015.

Meanwhile in Charleston Thursday, a diverse group of people gathered at the Second Presbyterian Church for a service paying tribute to the victims.

Clementa Pinckney, who was 41 and the pastor of Emanuel, was among the victims. He was also a South Carolina state senator.

The other victims were Cynthia Hurd, 54, a librarian; the Reverend Sharonda Coleman-Singleton, 45, a high school track coach; Tywanza Sanders, 26, a barber; church sexton Ethel Lance, 70; church member Susie Jackson, 87; the Reverend DePayne Middleton-Doctor, 49; vicar's wife, Myra Thompson, 59, and the Reverend Daniel Simmons, 74.

A visibly frustrated President Barack Obama said Thursday he will not hold back his emotions. He said this type of mass violence does not happen in other advanced countries with so much frequency.

"I've had to make statements like this too many times. Communities like this have had to endure tragedies like this too many times ... once again, innocent people were killed, in part, because someone who wanted to inflict harm had no trouble getting his hands on a gun."

Obama said he personally knew Pinckney.

WATCH: President Obama's statement on shooting

A yi hakuri, babu wannan abinda ake nema yanzu a shafin nan

Richard Cohen, head of the pro-civil rights Southern Poverty Law Center, told VOA that the shooting suspect Roof can be clearly seen wearing a pro-apartheid South African patch in a photographs seen on social media.

“I mean it is classic white supremacy violence. ... Instead of being someone with no future, he is going to be a world historic figure who has struck a blow for the white race. That appears to be what is at work in this case," Cohen said.

Emanuel AME Church was founded in 1816 after splitting from the city's white Methodist Episcopal church, making it one of the oldest African-American congregations in the southern United States. One of its founders, Denmark Vesey, was executed in 1822 for his involvement in a slave revolt.

The shootings are the latest in a long stream of mass shootings in the U.S., among them the the 2007 Virginia Tech shooting, when 32 were killed, and the 2012 Sandy Hook elementary school shooting in Newtown, Connecticut, where 27 people were killed, including 20 children.

The attack also comes at a time of heightened tension in America after several high-profile killings of unarmed black men at the hands of white police have triggered protests and a national debate on race.

One such case occurred in neighboring North Charleston, where Michael Slager, a white police officer, was charged with murder after he shot Walter Scott, an unarmed black man, in the back.